Numerous companies have pursued ball-type embolization devices for aneurysm treatment. Many of these, including the Nfocus LUNA device and other embodiments disclosed in commonly-owned patent applications are designed to be sized to fit a given aneurysm when the implant is fully deployed outside a delivery catheter. The same is true for the braid-ball implants disclosed and produced by Sequent Medical, Inc.
At least with the LUNA device, if size as visualized upon deployment (under active x-ray—i.e., “medical imaging”) is acceptable to a physician, the implant is detached. If not, the device is retrieved and exchanged for a more appropriate size. No example of devices designed for intra-aneurysmal treatment are known in which confirmation of final sizing is accomplished under medical imaging where the implant is deployed only up to a pre-selected or identified point. Certainly, embolization coils are often partially deployed within an aneurysm and visualized to determine if their size and/or configuration is acceptable before further advancing the same and effecting release. However, these are not deployed to a specified point as marked on the delivery system for making a size check.